1. Technical Field
The present invention relates to a method and apparatus for scrubbing foreign material from internal and external surfaces of a part such as a casting.
2. Background Art
In many manufacturing and assembly processes foreign material may be adhered to or deposited on the internal and external surfaces of the part being manufactured. The foreign material must be removed before the part is put into an assembly or into use.
A specific example of the general problems is in the casting industry wherein a variety of metal casting processes are used, with one such process involving the use of inexpensive styrofoam patterns which have been coated with a ceramic-type material. The patterns can be formed with intricate shapes having depressions, cavities, internal passages, crevices, chambers and the like. The pattern is positioned in a mold box and sand is formed therearound ready for casting. During the casting process, the styrofoam pattern melts away while the ceramic-type coating holds its shape long enough to form the metal casting. The ceramic type coating however also breaks up during the process and in doing so leaves particles of coating of foreign material or of sand adhered to the internal and external surfaces of the casting. Such particles or foreign material are, of course, undesirable in the finished product, and thus it is desirable to remove those particles. However, inasmuch as many castings will have internal passages, hole, crevices, chambers and the like which are hard to reach, the removal of those particles is difficult.
All molding systems suffer, in varying degrees, the same shortcomings namely, leaving residual particles or foreign material of the pattern and the molding sand on the external surfaces and in the internal surfaces of the castings. The residual particles need to be purged from the casting before the casting is processed further and/or put into use.
The present invention is directed toward overcoming one or more of the problems as set forth above.